I spent a few weeks with the S1 on both my trusty LampizatOr Pacific 2 DAC plus a Playback Design MPD-6 with MPD-X digital interface and Weiss Helios. The latter is JPLAY certified so the Weiss crew thoroughly tested the software and signed off. So did I. I've been with my custom Roon server for quite some years upgrading it from time to time. I think that it offers really good performance partly due to JCAT's components. Yet switching to the XACT showed almost instantly how the USB signal presenting at a top DAC's input can still significantly improve. This entailed unplugging a DL Custom Audio Emerald Mk2 USB cable from JCAT's XE USB card powered by Ferrum's Hypsos Signature installed in my server and plugging it into the S1's USB instead. It was an eye opener how much room there was for improvement over my DIY server. Since the XACT features several custom components unavailable for DIYers plus custom software, it's unlikely that I could ever achieve similar results with my home brew. The difference was undeniable but it still took some time to identify why I liked JCAT's server so much more and why it engaged this music lover more deeply.

The first impression was somewhat similar. My server and the S1 dispatching digital signal to my Pacific 2 and other DACs felt astoundingly analogue ie non-fatiguing and natural. As far as I know, Marcin is a digital guy to the bone yet each component of his I've sampled delivers performance best summed up as analogue-like. No wonder that I started with mostly acoustic albums like Jacques Loussier's 1979 Pulsion. Here the maestro's piano is accompanied by Luc Heller's drums. I love the album for its pure raw energy and like to use it for reviews. With my server it sounds crazy good each time it plays. It's fast, dynamic, explosive even and keeps me smiling. Yet with the S1 I heard even "more music in the music" although it's just two instruments. The piano was still more vibrant, sonorous and majestic. Decays seemed a bit longer. This fed the impression of 'more' music. While the instrument was properly big and massive over my server already, the S1 rendered it even more so with its potent, saturated, tuneful and beautifully fluid reading.

While my server and its ancillaries benefit from a few linear power supplies (one each for the server, switch and NAS plus a hybrid supply for the XE USB card), the XACT seemed to suffer even less from all the noise on my grid and home network. The background became even inkier and more velveteen. It may not read like much but in person it translated to deeper tone, higher resolution and more clarity of even the tiniest details. The latter enriched the presentation, completed it and made it more exciting and attention-grabbing. While there was even more data, the whole felt smoother and more coherent. It's what made the musical flow remind me—hard though it is to admit—of my excellent vinyl setup. Interestingly, the S1 paired with either of the three DACs reminded me of my J.Sikora turntable also in terms of how dynamic, focused and energetic it played. Yet when compared directly using the same preamplifier, amplifier and speakers, Peter Gabriel's So, Dire Straits' Love Over Gold or Ray Brown Trio's Soular Energy offered an even more focused precise sound and particularly tighter, deeper and more powerful bass over vinyl.  Still, I stand by my initial assessment. Both analog and digital sourced shared a lot of DNA to explain why I enjoyed the S1 so much.

Over my DIY server it seemed to widen the soundstage which combined with the abundance of information and amazing richness created a more immersive experience. And while it seemed that the incredibly fast, dynamic and powerful kick drum was a touch softer than over my server, I still thought that it kicked even more powerfully. And the energy of the performance was still higher. It wasn't quite the same as live but when I cranked up the volume, it got pretty close. Listening to the live "Saturday Night In San Francisco", I felt just a little bit more involved so emotionally closer to the three guitar players and their quite noisy highly invested audience. My server is very good at differentiating the guitars, their personalities and positioning on stage. It separates out each instrument so I can follow each whenever I choose. But the S1 bettered it all in still more convincing fashion with higher charge as well as still more precise detail retrieval without getting analytical. This included the venue acoustics so audible space which rendered clearly more 'visible' than over my server.